JP3296165B2 - Hydroperoxide decomposition method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for decomposing a hydroperoxide. More specifically,
The present invention relates to a method for decomposing hydroperoxide in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in a liquid phase in the presence of an acid catalyst to convert the same into dihydroxybenzene and acetone. The present invention relates to a hydroperoxide decomposition method which is suppressed to a level and is also thermoeconomically advantageous.

[0002]

2. Description of the Related Art A method for obtaining dihydroxybenzene and acetone by subjecting diisopropylbenzene to air oxidation to form diisopropylbenzene dihydroperoxide and further decomposing the diisopropylbenzene in the presence of an acid catalyst is known. is there.
Here, examples of dihydroxybenzene include resorcinol and hydroquinone. Meanwhile, as a method for decomposing the above diisopropylbenzene dihydroperoxide, diisopropylbenzene dihydroperoxide is converted into dihydroxybenzene and acetone by decomposing it in the presence of an acid catalyst, and then, the obtained dihydroxybenzene is obtained. It has been customary to separate and recover dihydroxybenzene and acetone by subjecting a mixed solution of acetic acid and acetone to rectification (see, for example, JP-A-53-95929). However, this method has a problem that a considerable amount of tar is produced as a by-product during the decomposition reaction. The generation of the tar causes loss of the target substances, dihydroxybenzene and acetone, and the generated tar adheres to the reaction apparatus and the piping, making smooth operation difficult, and in addition, additional tar for separating the tar. This is extremely inconvenient, especially from the viewpoint of industrial implementation.

[0003]

Under such circumstances, an object to be solved by the present invention is to subject diisopropylbenzene dihydroperoxide to a decomposition reaction in a liquid phase in the presence of an acid catalyst to obtain dihydroxybenzene and dihydroxybenzene. A method for decomposing a hydroperoxide that converts to acetone,
An object of the present invention is to provide a hydroperoxide decomposition method that suppresses the production of tar to a low level and is also advantageous in terms of thermoeconomics.

[0004]

That is, the present invention provides a method for decomposing diisopropylbenzene dihydroperoxide in a liquid phase in the presence of an acid catalyst to convert it into dihydroxybenzene and acetone. The present invention relates to a method for decomposing a hydroperoxide having the following characteristics (A) and (B). (A): Using a cracking reactor equipped with a rectification tower at the top, supplying a cracking raw material liquid and an acid catalyst to the cracking reactor, and allowing the cracking reaction to proceed from the top of the rectification tower while allowing the cracking reaction to proceed. (B): The concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid supplied to the decomposition reactor is at least partly removed from the reaction system.
~ 25% by weight

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a method for decomposing hydroperoxide in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in a liquid phase in the presence of an acid catalyst to convert into dihydroxybenzene and acetone.

[0006] Examples of diisopropylbenzene dihydroperoxide include metadiisopropylbenzene dihydroperoxide and paradiisopropylbenzene dihydroperoxide. These compounds are usually obtained by air oxidation of the corresponding diisopropylbenzene. At this time, diisopropylbenzene dihydroperoxide is usually first extracted from the oxidation reaction solution of diisopropylbenzene into an aqueous layer with an alkali, and further obtained as an organic solvent solution by re-extracting the alkaline aqueous layer with an organic solvent. Can be In addition, a compound having a 2-hydroxy-2-propyl group mixed in a small amount into diisopropylbenzene dihydroperoxide may interfere with the decomposition reaction, and thus is removed in advance by rectification or extraction. Is preferred.

[0007] The decomposition reaction is performed in a liquid phase. As a solvent at the time of the reaction, ketones such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane; Alcohols such as methanol, ethanol and propanol; benzenes such as benzene, toluene and xylene; and mixtures thereof are commonly used. Among these, it is preferable from an industrial viewpoint to use the organic solvent used for the re-extraction as the solvent for the main decomposition reaction. Also,
Solvents that are stable under decomposition reaction conditions using an acid catalyst are preferred. From these viewpoints, ketones are preferable, and methyl isobutyl ketone is particularly preferable.

Examples of the acid catalyst include sulfuric anhydride; benzenesulfonic acids such as p-toluenesulfonic acid; methanesulfonic acid, trichloromethanesulfonic acid, trifluoromethanesulfonic acid, perchloric acid, phosphoric acid, hydrochloric acid, hydrogen fluoride,
Examples include trichloroacetic acid, trifluoroacetic acid, aluminum chloride, boron trifluoride, a boron trifluoride complex, a cation exchange resin, and a compound having properties as an antioxidant containing a sulfur atom or the like can also be used. . Among them, sulfuric anhydride is preferred from the viewpoint of decomposition yield. The amount of the acid catalyst used is 0.005 to 5
A range of weight% is preferred. If the amount is too small, the intended decomposition reaction may not proceed sufficiently, while if the amount is too large, the reaction may proceed and the production of tar may increase. When sulfuric anhydride is used as the acid catalyst, the amount used is preferably in the range of 50 to 150 ppm by weight of the decomposition raw material liquid. Sulfuric anhydride is usually supplied to a decomposition reactor in a solution state dissolved in acetone. The concentration of the acid catalyst in the acetone solution is usually 0.1 to 10% by weight.

The preferred temperature and pressure conditions for the decomposition reaction are as follows: a temperature of 60 to 100 ° C. and a pressure of 200 to 700 Torr.
r can be given. If the decomposition temperature is too low, the intended decomposition reaction may not proceed sufficiently, while if the decomposition temperature is too high, the production of tar may increase. If the decomposition pressure is too low, the reaction temperature may not be maintained at a high level, while if the decomposition pressure is too high, the temperature required for distilling off the acetone may increase, and the production of tar may increase. The preferred decomposition reaction time (residence time in the decomposition reaction zone) is 1 to 15 minutes. If the decomposition reaction time is too short, the intended decomposition reaction may not proceed sufficiently, while if the decomposition reaction time is too long, the reaction may proceed and the production of tar may increase. Since the decomposition reaction involves a large amount of heat generation, a cooler is provided in the reactor to maintain the above reaction temperature, and the reaction is performed while cooling.

The present invention uses a cracking reactor having a rectification column at the top, supplies a cracking raw material liquid and an acid catalyst to the cracking reactor, and allows the cracking reaction to proceed and from the top of the rectification column. It is carried out by removing at least a part of acetone generated in the decomposition reaction out of the reaction system.

A decomposition reactor having a rectification column at the top means a reactor having a rectification column for performing a decomposition reaction and a rectification column installed directly above the reaction tank. means. The reaction tank is provided with cooling means for maintaining the reaction temperature. As the rectification column, a tray type or packed column type is used. As is clear from the structure of the reactor described above, of the reaction products generated in the reaction tank, acetone having a low boiling point and a part of the reaction solvent rise in the rectification column and are distilled from the top of the column. Is done. The distilled components are cooled and condensed by a cooler, and a part of the condensed liquid components is returned to the rectification column as reflux, and the remainder is removed from the reaction system by being sent to a post-process. Is done. Here, the amount of acetone generated by the decomposition reaction removed outside the system is preferably 30% or more of the total amount of acetone generated by the decomposition reaction. As a result, by-products of tar accompanying the decomposition reaction can be maintained at a lower level.

In the present invention, the concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid supplied to the decomposition reactor needs to be 10 to 25% by weight, and more preferably 15 to 20% by weight. It is necessary to be. If the concentration is too low, the productivity of the target substance per reactor volume decreases, and the energy required for the solvent separation in the subsequent step increases, which is industrially disadvantageous, while if the concentration is too high, the generation of tar increases. I do. Here, the decomposition raw material liquid is a solution containing diisopropylbenzene dihydroperoxide in a solvent, and as the solvent, those listed above as the solvent during the reaction are used. That is, the solvent constituting the decomposition raw material liquid becomes a solvent during the decomposition reaction. Since water in the decomposition raw material liquid may reduce the activity of the acid catalyst, the decomposition raw material liquid is preferably subjected to distillation in advance to reduce the water content in the decomposition raw material liquid to 1% by weight or less.

In the present invention, diisopropylbenzene dihydroperoxide, a solvent and an acid catalyst are supplied to a decomposition reactor as main components. Then, acetone and a part of the solvent are recovered from the top of the rectification column, and a mixed solution composed of dihydroxybenzene, tar, the solvent, and a part of the acetone is recovered.

Although the present invention is usually carried out as a continuous process, it is preferable to maintain the concentration of diisopropylbenzene dihydroperoxide in the entire decomposition reaction solution in a steady state at 0.5% by weight or less. This keeps tar by-products at a lower level and avoids safety issues associated with hydroperoxide explosions.

According to the present invention, by-products of tar during the decomposition reaction can be suppressed to a low level. As a reason for this, the present inventors presume as follows as a result of studies. That is, dihydroxybenzene and acetone react in a heated environment to produce tar, but in the present invention, dihydroxybenzene and acetone are formed by regulating the concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid to a relatively low level. The chances of tarification were also reduced by keeping the concentrations of dihydroxybenzene and acetone low, and reducing the chance of the tarification reaction, and immediately removing the generated acetone out of the system by rectification. This would have prevented the by-product of tar.

Further, the present invention directly utilizes heat generated in the decomposition reaction as a heat source for rectification, which is an advantageous method from the viewpoint of thermal economy.

[0017]

【Example】

Example 1 Metadiisopropylbenzene dihydroperoxide (m-DHPO) 1 was placed in a special reaction flask equipped with a 100 ml sphere portion as a reaction tank and a rectification tower above the sphere portion.
Methyl isobutyl ketone containing 9.9% by weight (MIB
K) 80 ml of a solution (reaction raw material liquid) was charged. The reaction raw material liquid used was a MIBK solution of m-DHPO obtained by air oxidation of diisopropylbenzene. While stirring the reaction raw material liquid, a reaction raw material liquid and an acetone solution of sulfuric anhydride (sulfuric anhydride concentration: 0.4% by weight) were further separately supplied to the flask at 1407 g / hr and 36.5 g / hr, respectively. . At this time, the amount of sulfuric anhydride relative to the reaction raw material liquid was 101 ppm by weight. The decomposition reaction was performed at a pressure of 520 Torr while maintaining the temperature of the reaction solution at 90 ° C. The residence time was 3 minutes. The light-boiling components such as generated acetone rise in the rectification column, and 116.8 g /
At hr, it was withdrawn as a distillate outside the system, while liquid components in the reaction tank such as resorcin were withdrawn at 1326.4 g / hr from the overflow of the flask as bottoms. The distilling ratio of acetone (acetone removed outside the system / total acetone distilled from the top of the rectification column × 100) was 45%. The bottom liquid and distillate were collected and analyzed only for 40 minutes when the inside of the system was stable. As a result, the material recovery rate of the entire system was 99.98%, and the decomposition yield [recovered total resorcinol (mol) / MD supplied
HPO (mol) × 100] is 92.6%, and the yield of tar component [recovered tar (g) / m-DHP supplied]
O (g) × 100] was 5.18%.

The m-DHPO concentration used to calculate the decomposition yield and tar component yield was determined by sodium thiosulfate titration and liquid chromatography, the resorcinol concentration was determined by gas chromatography, and the tar component concentration was determined by gel permeation. Analysis was carried out by a chromatography (GPC) method, and the obtained values were used.

Examples 2 to 3 and Comparative Examples 1 to 4 The same procedures were performed as in Examples except that the conditions shown in Table 1 were used.
The results are shown in Table 1. The following can be seen from the results. All examples satisfying the conditions of the present invention have shown satisfactory results. On the other hand, in Comparative Examples 1, 3 and 4 using a decomposition raw material liquid having an excessively high concentration of metadiisopropylbenzene dihydroperoxide, and using a decomposition raw material liquid having an excessively high concentration of metadiisopropylbenzene dihydroperoxide, Comparative Example 2 in which acetone was not removed from the upper part of the distillation column showed that the decomposition yield was low and the tar yield was high, and that there were many by-products of tar.

[0020]

[Table 1]

[0021]

Table 2 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative Example 1 2 3 4 Conditions Reaction temperature ℃ 90 75 105 100 Reaction pressure Torr 510 306 760 760 Residence time min 2.9 9.6 4.4 3.0 Acid catalyst amount wt ppm * 1 102 57 35 103 m-DHPO concentration wt% * 2 27.1 28.3 27.8 27.5 ACT Distillation ratio% * 3 47 0 49 39 Result Decomposition yield % * 4 89.8 83.5 81.1 85.7 Tar yield% * 5 6.43 6.58 8.86 8.98 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

* 1 Amount of acid catalyst: ratio to decomposition raw material liquid * 2 m-DHPO concentration: concentration of metadiisopropylbenzene dihydroperoxide in decomposition raw material liquid * 3 ACT distilling ratio: acetone removed from outside the system Total acetone distilled from the top of the distillation tower × 100 * 4 Decomposition yield: Total recovered resorcinol (mol) / m-DHPO supplied (mol) × 100 * 5 Tar yield: Collected tar (g) / Supplied m
-DHPO (g) x 100

[0023]

As described above, according to the present invention, a method for decomposing hydroperoxide in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in a liquid phase in the presence of an acid catalyst to convert into dihydroxybenzene and acetone. Thus, it was possible to provide a hydroperoxide decomposition method that suppresses the production of tar by-products to a low level and is also advantageous in terms of thermoeconomics.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C07C 45/53 C07C 45/53 49/08 49/08 A // C07B 61/00 300 C07B 61/00 300 (58) Field surveyed (Int. .Cl. ⁷ , DB name) C07C 39/00 C07C 37/00 C07C 45/00 C07C 49/00 C07C 27/00

Claims (1)

(57) [Claims] 1. A method for decomposing a hydroperoxide in which diisopropylbenzene dihydroperoxide is subjected to a decomposition reaction in a liquid phase in the presence of an acid catalyst to convert it into dihydroxybenzene and acetone. A method for decomposing a hydroperoxide having the feature (B). (A): Using a cracking reactor equipped with a rectification tower at the top, supplying a cracking raw material liquid and an acid catalyst to the cracking reactor, and allowing the cracking reaction to proceed from the top of the rectification tower while allowing the cracking reaction to proceed. (B): The concentration of diisopropylbenzene dihydroperoxide in the decomposition raw material liquid supplied to the decomposition reactor is at least partly removed from the reaction system.
~ 25% by weight